Fiber reinforced cement siding and anti-seismic reinforced structure of building using the fiber reinforced cement siding

ABSTRACT

The present invention relates to an anti-seismic reinforced structure of a building, and particularly to a fiber reinforced cement siding and an anti-seismic reinforced structure of a building using the fiber reinforced cement siding for improving moisture transmission performance by using a structural face material such as a fiber reinforced cement external wall material and the like in a wooden building.

BACKGROUND OF THE INVENTION

In conventional wooden buildings which are built by the existing framework construction method, the horizontal rigidity and horizontal strength of the entire structure are increased by attaching structural plywoods and bracings to framework components such as columns, beams, girt, and sill, which constitute the structural frame, to improve the resistance to seismic shocks. An example of the structural plywoods used herein is that having a thickness of 12 mm or 9 mm, a longitudinal length of 8 syaku (242.4 cm) and a lateral length of 3 syaku (90.9 cm). An anti-seismic structure is formed by fixing such plywoods to portions corresponding to the outer periphery and a stud with nails at intervals of 150 mm.

A conventional example, as shown in FIG. 14, shows a bearing wall 6 fixed to a framework structure 5 by using a ‘known fiber reinforced cement siding 3 (hereinafter referred to as face material 3)’ having such a dimension that can connect an upper horizontal member 1 and a lower horizontal member 2 with a single face material with nails 4.

The entire front surface of this face material 3 is painted. (Painted portion 10)

An example of anti-seismic structures in which hard cemented chip boards, among other fiber reinforced cement sidings, are used as structural face materials is shown in Notification No. 1100 of the Ministry of Construction dated Jun. 1, 1981, in which a board having a thickness of 12 mm, a lateral length of 910 mm and a longitudinal length of 3030 mm is fixed to columns and studs in a similar manner with nails at intervals of 150 mm to render the resistance factor of wall about 2.0. Herein, although it is defined that a structure in which a hard cemented chip board having the size of 910 mm×3030 mm is installed as a structural face material is a bearing wall having the resistance factor of wall, there are not definitions regarding fiber reinforced cement sidings other than hard cemented chip boards.

The resistance factor of wall is a numerical value which indicates the strength of a bearing wall in the Building Standards Law, and the resistance factor of wall of 1.0 means that the standard strength per 1 m of a bearing wall is 1.96 kN. If a face material other than the structural face material defined in the notification mentioned above is used to produce a bearing wall having the resistance factor of wall, the approval of the Minister of Land, Infrastructure and Transport needs to be obtained.

However, painted fiber reinforced cement sidings which have been approved by the minister as bearing wall structures characteristically allow less water vapor to pass through than plaster boards and the like (less moisture-permeable). One of the general causes of occurrence of condensation is an insufficient amount of ventilation inside the room. When the amount of ventilation by mechanical ventilation (ventilation fan) and natural ventilation (opening and closing of windows) is insufficient, the water vapor generated indoors is likely to stagnate inside the room and within the wall body. Especially in winter, when water vapor stagnates within a wall body which faces the outdoor, the risk of condensation of the inside portion of the wall cooled by outside air is increased, and structural materials in the major structural portions such as columns and beams may be decayed. In general, in case of a non-bearing wall structure, the water vapor generated indoors is discharged to the outdoor through inner heat insulating materials such as plaster boards, glass wool on the indoor side and then a moisture-permeable waterproof sheet. However, in case of a bearing wall structure, structural face materials having low moisture transmission performances block the path of this water vapor and allow less water vapor to be discharged to the outdoor. This results in stagnation of water vapor within the wall body and generation of condensation within the wall body.

When a bearing wall structure is employed, water vapor stagnates within the wall body and structural materials are disadvantageously likely to decay.

As a solution to such a problem, Japanese Unexamined Laid-Open Patent Publication No. H10-280580 discloses a vapor-permeable bearing wall facing material. The publication discloses a vapor-permeable bearing wall facing material in which the moisture captured within a wall is discharged by providing holes for discharging water vapor on the bearing wall facing material to prevent corrosion of the wall (patent document 1). Moreover, Japanese Patent No. 3417400 discloses a ventilating exterior wall (patent document 2), while Japanese Unexamined Laid-Open Patent Publication No. H8-120799 discloses a ventilating layer panel (patent document 3). These inventions have achieved a certain improvement in moisture transmission performance by providing discharge holes (ventilating holes, through-holes). However, when a face material is produced, numerous holes (bores) need to be bored on the face material, which requires time to process. Accordingly, extra time is necessary and therefore the efficiency of production is disadvantageously lowered.

Meanwhile, there is a method of not painting the entire surface of a structural face material to improve moisture transmission performance. However, if no painting is applied, the long-term strength of the structural face material and the long-term bearing strength of the bearing wall are greatly lowered. This is particularly because nailed portion and screw-fixed portions of the structural face material are deteriorated. Taking this deterioration into consideration, in the calculation of the resistance factor of wall of the bearing wall, a reduction coefficient is set for considering the deterioration of the structural face material of the nailed portions and screw-fixed portions. The method by which painting is not applied on the entire surface of the structural face material has the problem of a lowered strength of the bearing wall.

BRIEF SUMMARY OF THE INVENTION

The present device relates to an anti-seismic reinforced structure of a building, and particularly to a fiber reinforced cement siding and an anti-seismic reinforced structure of a building using the fiber reinforced cement siding for improving moisture permeability by using a structural face material such as a fiber reinforced cement external wall material and the like in a wooden building.

The present invention was made to solve the above-mentioned known problems, and an object of the invention is to provide a fiber reinforced cement siding for improving moisture transmission performance by using a structural face material such as a fiber reinforced cement external wall material and an anti-seismic reinforced structure of a building using the fiber reinforced cement siding.

The above object of the present invention is achieved by a fiber reinforced cement siding used for a wall portion of a building, the fiber reinforced cement siding having on its surface a painted portion which is partially painted and an unpainted portion, and the painted portion comprising at least a predetermined surface region centered around a nailed portion or a screw-fixed portion.

The above object of the present invention is also achieved more effectively by a fiber reinforced cement siding used for a wall portion of a building, the fiber reinforced cement siding comprising, on its surface, a first painted portion comprising a first amount of paint applied, and a second painted portion comprising an amount of paint applied which is less than the first amount of paint applied, the first and second painted portions being formed by painting portions of the surface, and the first painted portion comprising at least a predetermined surface region centered around a nailed portion or a screw-fixed portion.

The above object of the present invention is also achieved more effectively by a fiber reinforced cement siding, wherein a recess is further formed on the surface of the fiber reinforced cement siding, and the unpainted portion is formed on the bottom face of the recess.

The above object of the present invention is also achieved more effectively by a fiber reinforced cement siding wherein a recess is further formed on the surface of the fiber reinforced cement siding, and the second painted portion is formed on the bottom face of the recess.

The above object of the present invention is also achieved more effectively by a fiber reinforced cement siding, wherein a projection and a recess are further partially formed on the surface of the fiber reinforced cement siding, and the unpainted portion is formed in a side face portion forming the side faces of the projection and recess.

The above object of the present invention is also achieved more effectively by a fiber reinforced cement siding wherein a projection and a recess are further partially formed on the surface of the fiber reinforced cement siding, and the second painted portion is formed in a side face portion forming the side faces of the projection and recess.

The above object of the present invention is also achieved more effectively by a fiber reinforced cement siding, wherein the value of the resistance to moisture permeation of the painted portion is 2.67 m2·h·kPa/g to 6.67 m2·h·kPa/g.

The above object of the present invention is also achieved more effectively by a fiber reinforced cement siding, wherein the value of resistance to moisture permeation of the first painted portion is 2.67 m2·h·kPa/g to 6.67 m2·h·kPa/g, and the value of resistance to moisture permeation of the second painted portion is lower than that of the first painted portion.

The above object of the present invention is also achieved more effectively by a fiber reinforced cement siding, wherein the fiber reinforced cement siding has a longitudinal width of 2727 mm or more but 3030 mm or less, and a lateral width of 910 mm or more but 2000 mm or less.

The above object of the present invention is also achieved more effectively by an anti-seismic reinforced structure of a building, wherein, in a structural frame comprising a pair of columns which are disposed to oppose each other to the right and left, an upper horizontal member and a lower horizontal member which are connected to each column, the fiber reinforced cement siding is in contact with the front surfaces of the upper horizontal member, lower horizontal member and each columns and is fixed to the contact portion on the front surfaces of the upper horizontal member, the lower horizontal member and each of the columns at predetermined intervals of 30 mm or more but 200 mm or less with a nail or a screw.

The above object of the present invention is also achieved more effectively by an anti-seismic reinforced structure of a building, wherein, in a structural frame comprising a pair of columns which are disposed to oppose each other to the right and left, and an upper horizontal member and a lower horizontal member connected to each of the columns, the fiber-reinforced cement siding being in contact with the structural frame in which a joint between the upper horizontal member or lower horizontal member and each of the column or between these components are coupled with a metal fitting or a reinforcing metal, and the metal fitting or reinforcing metal is coupled in a position not interfering with the fiber reinforced cement siding with which is in contact, or counter bores are formed on the upper horizontal member or lower horizontal member and each column in the portions corresponding to the shape and thickness of the metal fitting or reinforcing metal so that the metal fitting or reinforcing metal does not interfere with the fiber reinforced cement siding, and the metal fitting or reinforcing metal is embedded and coupled in the counter bores, and

the fiber-reinforced cement siding being fixed to the contact portion on the front surfaces of the upper horizontal member, the lower horizontal member and each of the columns at predetermined intervals of 30 mm or more but 200 mm or less with a nail or a screw.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view showing a typical example of the fiber reinforced cement siding according to Example 1 of the present invention.

FIG. 2 is a structural front view showing a typical example of an anti-seismic reinforced structure of a building using the fiber reinforced cement siding according to Example 1 of the present invention structure.

FIG. 3 is a structural top view showing a typical example of the anti-seismic reinforced structure of a building using the fiber reinforced cement siding according to Example 1 of the present invention.

FIG. 4 is a front view showing a typical example of the fiber reinforced cement siding of the present invention according to Example 2.

FIG. 5 is a front view showing a typical example the fiber reinforced cement siding according to Example 3 of the present invention.

FIG. 6 is a front view showing a typical example of the fiber reinforced cement siding according to Example 4 of the present invention.

FIG. 7 is a front view showing a typical example of the fiber reinforced cement siding according to Example 5 of the present invention.

FIG. 8 is a front view showing a typical example of the fiber reinforced cement siding according to Example 6 of the present invention.

FIG. 9 is a front view showing a typical example of the fiber reinforced cement siding according to Examples 7 and 8 of the present invention.

FIG. 10 is a cross-sectional view showing a typical example of the fiber reinforced cement siding according to Example 9 of the present invention.

FIG. 11 is a cross-sectional view showing a typical example of the fiber reinforced cement siding according to Example 10 of the present invention.

FIG. 12 is a cross-sectional view showing a typical example of the fiber reinforced cement siding according to Example 11 of the present invention.

FIG. 13 is a cross-sectional view showing a typical example of the fiber reinforced cement siding according to Example 12 of the present invention.

FIG. 14 is a structural front view showing a known bearing wall (Comparative Example).

DETAILED DESCRIPTION OF THE INVENTION

According to the fiber reinforced cement siding of the present invention and an anti-seismic reinforced structure of a building using the fiber reinforced cement siding, the moisture transmission performance of structural face materials can be improved without providing ventilating holes in the form of through-holes, and good effects as a bearing wall can be also exerted. Since the fiber reinforced cement siding is a noncombustible material or a quasi-noncombustible material, it can increase the resistance of a framework structure to fire and does not decay like wood. Therefore, durability can be ensured for a long period of time.

Hence, according to such a fiber reinforced cement siding of the present invention and the anti-seismic reinforced structure of a building using the fiber reinforced cement siding, the moisture transmission performance of the structural face material can be increased, and high resistance to condensation within the wall body, resistance to seismic shocks, resistance to fire and excellent durability (resistance to decay) are provided. Therefore, their advantages are remarkable.

BEST MODE FOR CARRYING OUT THE INVENTION

The most suitable embodiments of the present invention will be described with reference to FIGS. 1 to 14.

FIG. 1 and FIGS. 4 to 13 show fiber reinforced cement sidings according to embodiments of the present invention, and FIGS. 2 and 3 show anti-seismic reinforced structures of a building using this fiber reinforced cement siding.

FIG. 14 shows a known bearing wall (Comparative Example).

Example 1

Example 1 of the present invention, as shown in FIG. 1, is constituted of a fiber reinforced cement siding 9 (hereinafter referred to as board 9), which is a building face material, partially having a paint applied on its front surface. Nails 4 are driven only in a nailed portion 95 of a painted portion 11 which is partially painted (described later). Moreover, an unpainted portion 12 is provided on the front surface excluding the painted portion 11 which is partially painted.

In Example 1 of the present invention, as shown in FIGS. 2 and 3, the board 9 is affixed with the long sides oriented vertically to a framework structure 5 consisting of an upper horizontal member 1, a lower horizontal member 2, columns 7 and studs 8. Herein, the dimension of the board 9 is set depending on the intervals of the column 7 so that the left end 91 and right end 92 of the board 9 are in contact with the front surfaces of the columns 7. Similarly, the dimension of the board 9 is set depending on the interval between the upper horizontal member 1 and the lower horizontal member 2 so that the upper end portion 93 and lower end portion 94 of the board 9 are in contact with the front surfaces of the upper horizontal member 1 and the lower horizontal member 2.

In affixing the board, the lower end portion 94 of the board 9 is brought into contact with the front surface of the lower horizontal member 2, and the nails 4 are driven at intervals of 100 mm along the lower side of the board 9 in the direction of its shorter sides to fix the board 9. Furthermore, as for the portion in which the left end 91 and right end 92 of the board 9 mentioned above are in contact with the column 7, the nails 4 are driven at intervals of 100 mm along the left side and right side of the board 9 in the direction of its longer sides to fix the board 9. Moreover, in this board 9, a portion which is in contact with the stud 8 is fixed by driving the nails 4 at intervals of 200 mm in the direction of the longer sides of the board 9. A portion of the board 9 which is in contact with the upper horizontal member 1 at its upper end portion 93 is fixed by driving the nails 4 into the upper horizontal member 1 at intervals of 100 mm along the upper side of the board 9 in the direction of its shorter sides.

The painted portion 11 which is partially painted is provided only in the portions where the board 9 is in contact with the upper horizontal member 1, lower horizontal member 2, columns 7 and studs 8 constituting the framework structure 5, and their neighboring portions. The nails 4 are driven only in the nailed portion 95 in the painted portion 11 which is partially painted at predetermined intervals to fix the board 9.

Example 2

Example 2 of the present invention, as shown in FIG. 4, is constituted by a board 9 which is provided with a first painted portion 13 comprising a first amount of paint applied and a second painted portion 14 comprising a less amount of paint applied than the first amount of paint applied on its front surface. Nails 4 are driven only in the first painted portion 13 comprising the first amount of paint applied. Other conditions are the same as in Example 1.

Herein, the nails 4 used in conventional examples and Examples 1 and 2 according to the embodiments of the present invention have a shank diameter of 2.75 mm, a length of 50 mm, and smoothly shaped shanks. In each Example, if the intervals of the nails 4 driven to fix the board 9 to the upper horizontal member 1, the lower horizontal member 2 and the columns 7, i.e., 100 mm, is less than 30 mm, cracks are produced in the board. Therefore, it is desirable to drive the nails at intervals of 30 mm or more. Moreover, when the intervals of these nails 4, i.e., 100 mm, are more than 200 mm, strength is reduced. Therefore, it is desirable to drive the nails at intervals of 200 mm or less. For the same reason, the intervals of the nails 4 for fixing the board 9 to the studs 8, i.e., 200 mm is desirably 30 mm or more. If these intervals of 200 mm is more than 200 mm, warping and lifting in the out-of-plane direction and other problems of the board are produced, which is undesirable for exerting strength. Therefore, it is desirable to drive the nails at intervals of 200 mm or less.

It should be noted that the lower horizontal member is equivalent to a sill in the first floor of the framework structure, while it is equivalent to girts, beams and crossbeams in the second and higher floors. Moreover, the upper horizontal member is equivalent to girts, beams and crossbeams in the first and higher floors of the framework structure.

Example 3

In Example 3 of the present invention, as shown in FIG. 5, a painted portion 11 which is partially painted is provided in the form of circles in a nailed portion 95, and an unpainted portion 12 is provided in the rest of the front surface.

Also in this case, the positions of nails 4 in the board 9 are the same as in Examples 1 and 2 (not shown), but the area of the painted portion is smaller as a whole than in Example 1. Therefore, the resistance to moisture permeation tends to be lower (moisture transmission performance is increased). In other words, Example 3 tends to have a lower resistance to moisture permeation (moisture transmission performance is increased) than Comparative Example.

Example 4

In Example 4 of the present invention, as shown in FIG. 6, a first painted portion 13 comprising a first amount of paint applied is provided in the form of the circles in a nailed portion 95, and a second painted portion 14 comprising a less amount of paint applied than the first amount of paint applied is provided in the rest of the front surface. In this Example 4, a second painted portion 14 comprising a less amount of paint applied than a first amount of paint applied is provided in the range of the unpainted portion 12 shown in Example 3. The range of a first painted portion 13 comprising the first amount of paint applied is identical to the painted portion 11 which is partially painted in Example 3.

Also in this case, the positions of nails 4 of the board 9 are the same as in Examples 1 and 2 (not shown), but the area of the first painted portion 13 comprising the first amount of paint applied is smaller than that of the painted portion 11 which is partially painted of Example 2. Therefore, the resistance to moisture permeation tends to be lower (moisture transmission performance is increased). In other words, Example 4 tends to have a lower resistance to moisture permeation than Comparative Example (moisture transmission performance is increased).

Example 5

As shown in FIG. 7 (a) to (c), in Example 5 of the present invention, the range of the painted portion 11 which is partially painted is larger and the range of the unpainted portion 12 is smaller than in Example 1. Although Example 5 tends to have a resistance to moisture permeation higher than Example 1, it can obtain an improving effect similar to Example 1.

Example 6

As shown in FIG. 8 (a) to (c), in Example 6 of the present invention, the range of a first painted portion 13 comprising a first amount of paint applied is larger, and the range of a second painted portion 14 comprising a less amount of paint applied than the first amount of paint applied is smaller than in Example 2. Although Example 6 tends to have a resistance to moisture permeation higher than Example 2, it can obtain an improving effect similar to Example 2.

Examples 7 and 8

As shown in FIG. 9 (a), (b), in Examples 7 and 8 of the present invention, a painted portion 11 which is partially painted and a first painted portion 13 comprising a first amount of paint applied are enlarged in the upper end portion 93 of the board 9 and the lower end portion 94 of the board 9 in the direction of the longer sides of the board 9, compared to Examples 1 and 2. More specifically, the areas of the painted portion 11 which is partially painted and the first painted portion 13 comprising a first amount of paint applied are increased to ensure that a nailed portion 95 is in contact with the painted portion 11 which is partially painted and the first painted portion 13 comprising the first amount of paint applied, considering cutting and fixing of the board 9 corresponding to the interval between an upper horizontal member 1 and a lower horizontal member 2 in the construction site. Examples 7 and 8 have an effect to improve moisture transmission performance similar to Examples 1 and 2, respectively, and have installation flexibility which allows cutting of the board depending on the installation parts and intervals in an optional position. They also have the effect to reduce installation failure such as nails driven into the portion other than the painted portion 11 which is partially painted and the first painted portion 13 comprising the first amount of paint applied.

Example 9

As shown in FIG. 10 (a) to (d) in Example 9 of the present invention, a number of recesses 20 are provided on the surface of the board, and painted portions 11 which are partially painted are further provided on the surface. Moreover, unpainted portions 12 are provided on bottom faces 22 and side faces (slope) 23 of the recesses 20. The method of fixing the board is similar to that in Example 1 (not shown). The unpainted portions 12 on the side faces (slope) 23 are increased by providing these recesses 20, and the moisture transmission performance is thus improved.

Example 10

As shown in FIG. 11 (a) to (d), in Example 10 of the present invention, a number of recesses 20 similar to those in Example 9 are provided on the surface of the board, and first painted portions 13 comprising a first amount of paint applied are further provided on the surface. Moreover, second painted portions 14 comprising a less amount of paint applied than the first amount of paint applied are provided on bottom faces 22 and side faces (slope) 23 of the recesses 20. The method of fixing the board is similar to that in Example 2 (not shown). The second painted portions 14 comprising a less amount of paint applied than the first amount of paint applied are increased by providing these recesses 20 on the side faces (slope) 23, and the moisture transmission performance is thus improved.

Example 11

As shown in FIG. 12 (a) to (d), in Example 11 of the present invention, a number of projections 21 are provided on the surface of the board, and painted portions 11 which are partially painted are further provided on the top surfaces of the projections 21. Moreover, unpainted portions 12 are provided in the portion other than the top surfaces of the projections 21. The method of fixing the board is similar to that in Example 1 (not shown). The unpainted portions 12 on the side faces (slope) 23 are increased by providing these projections 21, and the moisture transmission performance is thus improved.

Example 12

As shown in FIG. 13 (a) to (d), in Example 12 of the present invention, a number of projections 21 are provided on the surface of the board, and first painted portions 13 comprising a first amount of paint applied are further provided on the top surfaces of the projections 21. Moreover, second painted portions 14 comprising a less amount of paint applied than the first amount of paint applied are provided in the portion other than the top surfaces of the projections 21. The method of fixing the board is similar to that in Example 2 (not shown). The second painted portions 14 comprising a less amount of paint applied than the first amount of paint applied on the side face (slope) 23 are increased by providing these projections 21, and the moisture transmission performance is thus improved.

Although not shown in the Figs., the framework structure is constituted by using metal fittings or reinforcing metals in some forms. Also in this case, Examples 1 to 12 can be applied.

Similarly, when the metal fittings or reinforcing metals function as anti-seismic reinforcing metals and the framework structure has a performance of a strength wall structure, these Examples 1 to 12 can be applied to constitute a composite bearing wall.

Subsequently, the results of the tests for comparing the fiber reinforced cement siding according to embodiments of the present invention and an anti-seismic reinforced structure of a building using the fiber reinforced cement siding (Examples 1 and 2), and a known fiber reinforced cement siding and a bearing wall structure using the same (Comparative Examples) are shown in Tables 1 to 5.

<Method of Testing Moisture Transmission Performance>

Tests were conducted by a method according to the cup method described in Japanese Industrial Standards JIS A 1324 measuring method of water vapor permeance for building materials. It should be noted that the test relating to moisture transmission performance was carried out not by using a full-size wall structure, but by using sample pieces.

In addition, Japanese Industrial Standard JIS A 1324 Measuring method of water vapor permeance for building materials is the testing method which refers the testing method of the below-mentioned standard.

1. ASTM E96 Standard Method of Test for Water Vapor Transmission of Materials, American Society for Testing and Materials.

<Basic Test> TABLE 1 Table 1: Specimens and test results of “basic test of moisture transmission performance” Basic test specimen 3 (Comparative example Basic test Basic test (conventional specimen 1 specimen 2 example)) Schematic two- dimensional configuration of specimen

Sample Fiber reinforced cement siding Size of sample 290 x 290 mm Thickness of 9mm sample Area of moisture Inner 250 x 250 mm permeation Type of paint Acrylic emulsion paint Amount of paint (1): None (2): 75 (3): 130 applied (g/m²) Resistance to 0.56 1.49 3.31 moisture (4.2) (11.2) (24.8) permeation (m².h.Pa/g) (m².h.mmHg/g inside ()) Result Excellent Good — Remarks: The smaller the value of resistance to moisture permeation, the better.

<Control Specimens> TABLE 2 Table 2: Profile of control specimens of moisture transmission performance Comparative example (conventional Example 1 Example 2 example) Schematic two- dimensional configuration of specimen

Sample Fiber reinforced cement siding Size of sample 290 x 290 mm Thickness of 9 mm sample Area of moisture Inner 250 x 250 mm permeation Type of paint Acrylic emulsion paint Painting (1): Unpainted (2): Second (3): Painted specification portion painted portion portion (3): Painted comprising an portion which is amount of paint partially painted applied which is less than first amount of paint applied (3): First painted portion comprising first amount of paint applied Ratio of painted (1): 50% (2): 50% (3): 100% areas (3): 50% (3): 50% Remarks Painting of (2) and (3) are the same as the painting specification of the basic test in Table 1.

<Comparative Test Results of Moisture Transmission Performance> TABLE 3 Comparative test results of moisture transmission performance Comparative Example (conventional Example 1 Example 2 example) Resistance to 0.85 1.93 3.31 moisture (6.4) (14.5) (24.8) permeation (m² · h · kPa/g) (m² · h · mmHg/g inside ( )) Result Excellent Good — Remarks: The smaller the value of resistance to moisture permeation, the better.

<Method of Testing Strength of Bearing Wall>

The test was conducted by a test method in conformity with the approval prescribed in the Ordinance for Enforcement of the Building Standards Law Article 46 (4), item (8) in Table 1 “Manual of method of testing and evaluating operations of wooden bearing walls their factors of resistance” published by the designated performance evaluation organization defined in the Building Standards Law Article 77 (56) and Ordinance relating to designated qualification certification organization under the Building Standards Law Article 71 (2).

This testing method is basically the same as the testing method of the following standard.

1. Japanese Industrial Standated. (1994). JIS A 1414 Methods of Performance Test of Panels for Building Construction. (6.14)

2. ASTM E564-95. (1995). Standard Method of Static Load Test for Shear Resistance of Framed Walls for Buildings, American Society for Testing and Materials.

3. ASTM E72-02. (2002). Standard Methods of Conducting Strength Tests of Panels for Builing Construction, American Society for Testing and Materials.

<Specimen> TABLE 4 Profile of specimens Comparative Example (conventional Example 1 Example 2 example) Size of framework 1,820 mm (width) × 2,730 mm (height) material Material of Upper horizontal member: Douglas fir framework Lower horizontal member, columns, studs: Pine material Dimensions of Upper horizontal member: 180 mm × 105 mm members of Lower horizontal member: 105 mm × 105 mm framework Columns: 105 mm × 105 mm material Studs: 105 mm × 45 mm Structural face Fiber reinforced cement siding thickness: 9 mm material 910 mm (shorter sides) × 2730 mm (longer sides) Acrylic emulsion paint Paint Paint Paint specification: specification: specification: Painted portion First painted Painting on the which is partially portion entire front painted comprising first surface Resistance to amount of paint Resistance to moisture applied moisture permeation: 3.31 Resistance to permeation: 3.31 m² · h · kPa/g moisture m² · h · kPa/g Unpainted permeation: 3.31 portion m² · h · kPa/g Resistance to Second painted moisture portion permeation: 0.56 comprising less m² · h · kPa/g amount of paint applied than first amount of paint applied Resistance to moisture permeation: 1.49 m² · h · kPa/g Nail intervals Left and right ends of board: 100-mm intervals to columns Center of board: 200-mm intervals to studs Lower end of board: 100-mm intervals to lower horizontal member Upper end of board: 100-mm intervals to upper horizontal member Nails Shank diameter: 2.75 mm, length: 50 mm (Configuration of shank: smooth)

<Tests on Strength of Bearing Wall Results> TABLE 5 “Data of Load-angle of deformation” of Example 1, Example 2 and Comparative Example Comparative Angle of Example deformation (conventional (rad) Example 1 Example 2 example) 1/450 7.25 8.35 7.80 1/300 9.15 10.75 9.80 1/200 11.85 13.80 12.75 1/150 13.70 15.60 14.55 1/100 16.95 19.30 17.80 1/75 19.05 21.25 19.75 1/50 22.35 24.05 23.45

<Test Results>

The comparative test results of moisture transmission performance indicate that the moisture transmission performance of Examples 1 and 2 was improved compared to Comparative Example. Moreover, the results of the tests on strength of bearing wall indicate that the strength of Examples 1 and 2 and Comparative Example are similar, and even if there is an unpainted portion as in Example 1 or there is a portion where the amount of the paint applied is low as in Example 2, sufficient strength can be obtained.

It is understood from these results that even if painting is partially applied on a single fiber reinforced cement siding and a painted portion which is partially painted is provided to reduce the painted area as a whole, Example 1 can realize a fiber reinforced cement siding having excellent anti-seismic performance and improved moisture transmission performance and an anti-seismic reinforced structure of a building using the fiber reinforced cement siding.

Similarly, even when both of the first painted portion comprising the first amount of paint applied and the second painted portion comprising an amount of paint applied which is less than the first amount of paint applied are provided, Example 2 can realize a fiber reinforced cement siding having excellent anti-seismic performance and improved moisture transmission performance and an anti-seismic reinforced structure of a building using the fiber reinforced cement siding.

Regarding the structural frame in the fiber reinforced cement siding of the present invention and an anti-seismic reinforced structure of a building using the fiber reinforced cement siding, such structural frames that are constructed by the framework construction method are mainly described above, but construction methods other than this, for example, the wood frame construction method and the log construction method can be similarly applied.

As the structural frame in the fiber reinforced cement siding of the present invention and the anti-seismic reinforced structure of a building using the fiber reinforced cement siding, there are framework construction methods and structures based on the scale dimensions such as the syaku module in which the intervals between the columns and the studs are 455 mm and the meter module in which the intervals are 500 mm. When the fiber reinforced cement siding is installed on these frameworks with the long sides oriented vertically, the lateral width of the board can be 910 mm or more but 1820 mm or less in case of the syaku module, or the lateral width can be 1000 mm or more but 2000 mm or less in case of the meter module.

For example, in case of the syaku module, when a board having a lateral width of 910 mm and a longitudinal width of 3030 mm is provided in a tensioned state on a framework structure having a width of 1820 mm and a height of 2727 mm, two boards which are cut to have a longitudinal width of 2727 mm may be used.

Similarly, in case of the meter module, when a board, for example, having a lateral width of 1000 mm and a longitudinal width of 3030 mm is provided in a tensioned state on a framework structure having a width of 2000 mm and a height of 3000 mm, a board which has been cut to have a longitudinal width of 3000 mm may be used.

The thickness of the board is preferably 9 mm or more, but the thickness can be set depending on the required strength of the bearing wall even if the thickness is less than 9 mm.

Painting of the surface of the board may be carried out in any manner as long as it is suitable for fiber reinforced cement sidings. Examples include acrylic urethane-based resin paint, acrylic resin paint, acrylic silicon resin paint, fluorine-based resin paint, epoxy-based resin paint, inorganic paint and the like. These may be used singly or in combination. Moreover, various kinds of sealer paints may be also used singly. Moreover, combinations of the various kinds of sealer paints and the above-mentioned paints are also usable. Furthermore, painting may be also carried out dividedly for several times to form a plurality of coated films.

The values of the resistance to moisture permeation of the painted portion which is partially painted and the first painted portion comprising the first amount of paint applied are preferably 2.67 m2·h·kPa/g to 6.67 m2·h·kPa/g, but they may be larger than 6.67 m2·h·kPa/g. In this case, an extent of a decrease in the long-term strength of the structural face material and a decrease in the long-term strength of the bearing wall can be reduced. On the other hand, in case where the required long-term performance of the design objective of the bearing wall is not high, the values of the resistance to moisture permeation of the painted portion which is partially painted and the first painted portion comprising the first amount of paint applied can be lower than 2.67 m2·h·kPa/g.

Furthermore, the value of the resistance to moisture permeation of the second painted portion comprising an amount of paint applied which is less than the first amount of paint applied is desirably lower than the value of the resistance to moisture permeation of the first painted portion comprising the first amount of paint applied. However, since the lower the value of the resistance to moisture permeation of the second painted portion comprising an amount of paint applied which is less than the first amount of paint applied, the more effective in improving moisture transmission performance, the difference between the value of the resistance to moisture permeation of the second painted portion comprising an amount of paint applied which is less than the first amount of paint applied and that of the first painted portion comprising the first amount of paint applied is desirably set large.

The painted portion which is partially painted and the first painted portion comprising the first amount of paint applied may be any portion as long as they are at least round region faces having a radius of 30 mm centered around the nailed portion or screw-fixed portion.

This circle having a radius of 30 mm represents the area of influence of the stress transmitted to the board by a fastener such as a nail and screw. If the range of each of the painted portion which is partially painted and the first painted portion comprising the first amount of paint applied is smaller than this circle having a radius of 30 mm, the strength of the nailed portion or screw-fixed portion of the board tends to be lowered. Therefore, the radius is desirably 30 mm or more. Moreover, when the strength of the bearing wall is further improved, this radius 30 mm is desirably a larger numerical value.

On the other hand, in case where the required performance of the bearing wall of the design objective is not high, this radius 30 mm can be smaller than this.

The recesses and the cross sectional shapes of the recesses and projections shown in Examples 9 to 11 may be chamfered at their corners. Moreover, the lines constituting the cross sections are not limited to combinations of straight lines, and may be curves and free-form curves. The vertical (depth) dimensions of the recesses and projections are desirably 0.5 mm or more. Furthermore, the recesses and the two-dimensional shapes (front shapes) of the recesses and projections may be a straight line, curve, free-form curve, circle, ellipse, polygon having three sides or more, geometrical pattern, symbol, character and any other shape, or combinations of these. The recesses and the two-dimensional sizes (front dimensions) of the recesses and projections may be at least 1 mm in diameter. In addition, small projections, recesses and grooves may be further provided on the surface of the board and the bottom faces and side faces (slope) of the recesses. For example, projections are provided on the board in a brick pattern, minute recesses are provided in these projections, and further mortar-patterned minute projections and recesses are provided in the recesses (joint portions between bricks) in some cases.

Similarly, when no recesses and projections are provided on the surface of the board, the two-dimensional shapes (front shapes) of the unpainted portion and the second painted portion comprising an amount of paint applied less than the first amount of paint applied may be also a straight line, curve, free-form curve, circle, ellipse, polygon having three sides or more, geometrical pattern, symbol, character or any other shape, or combinations of these. The two-dimensional size (front size) may be at least 1 mm in diameter.

In painting the board, a painted surface may be constituted in the form of planes, lines or spots by using a roll coater or the like. Similarly, painting in the form of minute spots may be applied by sputtering, ink jet, electrostatic coating or other methods to constitute the painted portion which is partially painted, the unpainted portion, the first painted portion comprising the first amount of paint applied, and the second painted portion comprising an amount of paint applied less than the first amount of paint applied.

Furthermore, in the second painted portion comprising an amount of paint applied less than the first amount of paint applied, a minute unpainted portion may be produced by sand-blasting a normal painted surface or conducting other processes so that a painted surface having a value of the resistance to moisture permeation similar to the second painted portion comprising an amount of paint applied less than the first amount of paint applied is obtained.

In order to ensure sufficient moisture transmission performance, regardless of whether recesses and projections are provided or not, it is desirable to provide a number of the unpainted portions and the second painted portions comprising an amount of paint applied less than the first amount of paint applied. However, the number and area of these portions may be set depending on required moisture transmission performance and aesthetic quality.

Furthermore, the fiber reinforced cement siding can be installed both on the external wall side and inner wall side of the board. When the durability of the bearing wall structure is to be ensured more securely, the outer surface of the board is desirably subjected to a finishing process on the external wall. The ends of this board may be chamfered, and the configuration of the joint portions between the boards may be butt joint, ship-lap, tongue-and-groove joint, or combinations of these. For example, when the board is used for interior work, a possible constitution is such that the ends of the chamfered boards are joined by butt joint to form a butt joint, and a filler such as a putty is applied in this joint to render the wall jointless.

When the board is installed on the external wall side, a moisture-permeable waterproof sheet (e.g., Tyvek manufactured by Du Pont) having a standardized configuration and dimension may be affixed in advance on the outer surface of the board depending on the shape and dimension of the board. Furthermore, in the right and left abutting portions and upper and lower abutting portions between the boards, it is desirable that one of the sides of the moisture-permeable waterproof sheet has an overlap allowance in such a shape that it extends slightly off the board so that the boards can be superposed on each other. In this case, the man-hours for affixing the moisture-permeable waterproof sheet at the construction site can be reduced.

In addition, in the vertical and horizontal edges of the board, when the end distance and edge distance of the nails or screws driven into the board is less than 15 mm, cracks may be generated in the board. Therefore, the end distance and edge distance of 15 mm or more are desirably ensured. The nail used is desirably the stainless steel nail defined by JIS A 5508, with a shank diameter of 2.75 mm or more, a length of 50 mm or more, and a smoothly shaped shank. As well as in the thickness of the board, it is possible to set iron round nails, nails for plaster boards and the like according to the above standard depending on the required resistance factor of wall and set the diameter, length and shape of the shank.

When the board is fixed by using screws, the screws used is desirably cross recessed countersunk head tapping screws defined by JIS B 1122 with a diameter of 3 mm or more and a length of 30 mm or more, or coarse threads. As in the above, it is possible to establish screws for plaster boards and light top tapping screws depending on the required resistance factor of wall and set the dimensions and shapes such as diameter and length. Moreover, in working the screws, to prevent breakage of the edge of the board, it is desirable that tap drill holes having the same diameter as the screws or a diameter slightly smaller than that of the screws are formed on the board in advance, and the screws are driven into these tap drill holes by using electric tools such as electric drivers to prevent breakage of the board. 

1: A fiber reinforced cement siding used for a wall portion of a building, the surface of the fiber reinforced cement siding having a painted portion which is partially painted and an unpainted portion, and the painted portion comprising at least a predetermined surface region centered around a nailed portion or a screw-fixed portion. 2: A fiber reinforced cement siding used for a wall portion of a building, the fiber reinforced cement siding comprising, on its surface, a first painted portion comprising a first amount of paint applied, and a second painted portion comprising an amount of paint applied which is less than the first amount of paint applied, the first and second painted portions being formed by painting portions of the surface, and the first painted portion comprising at least a predetermined surface region centered around a nailed portion or a screw-fixed portion feature. 3: A fiber reinforced cement siding according to claim 1, wherein a recess is further formed on the surface of the fiber reinforced cement siding, and the unpainted portion is formed on the bottom face of the recess. 4: A fiber reinforced cement siding according to claim 2, wherein a recess is further formed on the surface of the fiber reinforced cement siding, and the second painted portion is formed on the bottom face of the recess. 5: A fiber reinforced cement siding according to claim 1, wherein a projection and a recess are further partially formed on the surface of the fiber reinforced cement siding, and the unpainted portion is formed in a side face portion forming the side faces of the projection and recess. 6: A fiber reinforced cement siding according to claim 2, wherein a projection and a recess are further partially formed on the surface of the fiber reinforced cement siding, and the second painted portion is formed in a side face portion forming the side faces of the projection and recess. 7: A fiber reinforced cement siding according to claim 1, wherein the value of resistance to moisture permeation of the painted portion is 2.67 m2·h·kPa/g to 6.67 m2·h·kPa/g. 8: A fiber reinforced cement siding according to claim 2, wherein the value of resistance to moisture permeation of the first painted portion is 2.67 m2·h·kPa/g to 6.67 m2·h·kPa/g, and the value of resistance to moisture permeation of the second painted portion is lower than that of the first painted portion. 9: A fiber reinforced cement siding according to claim 1, wherein the fiber reinforced cement siding has a longitudinal width of 2727 mm or more but 3030 mm or less, and a lateral width of 910 mm or more but 2000 mm or less. 10: An anti-seismic reinforced structure of a building wherein, in a structural frame comprising a pair of columns which are disposed to oppose each other to the right and left, an upper horizontal member and a lower horizontal member which are connected to each of the columns, a fiber reinforced cement siding according to claim 1 is in contact with the front surfaces of the upper horizontal member, the lower horizontal member and each of the columns, and is fixed to the contact portion on the front surfaces of the upper horizontal member, the lower horizontal member and each of the columns at predetermined intervals of 30 mm or more but 200 mm or less with a nail or a screw. 11: An anti-seismic reinforced structure of a building wherein, in a structural frame comprising a pair of columns which are disposed to oppose each other to the right and left, an upper horizontal member and a lower horizontal member which are connected to each of the columns, a fiber reinforced cement siding according to claim 1 being in contact with the structural frame in which a joint between the upper horizontal member or lower horizontal member and each of the columns or between these components are coupled with a metal fitting or a reinforcing metal, and the metal fitting or reinforcing metal is coupled in a position not interfering with the fiber reinforced cement siding with which it is in contact, or, counter bores are formed on the upper horizontal member or lower horizontal member and each column in the portions corresponding to the shape and thickness of the metal fitting or reinforcing metal so that the metal fitting or reinforcing metal does not interfere with the fiber reinforced cement siding, and the metal fitting or reinforcing metal is embedded and coupled in the counter bores, and is fixed to the contact portion on the front surfaces of the upper horizontal member, the lower horizontal member and each of the columns at predetermined intervals of 30 mm or more but 200 mm or less with a nail or a screw. 12: A fiber reinforced cement siding according to claim 3, wherein the value of resistance to moisture permeation of the painted portion is 2.67 m2·h·kPa/g to 6.67 m2·h·kPa/g. 13: A fiber reinforced cement siding according to claim 5, wherein the value of resistance to moisture permeation of the painted portion is 2.67 m2·h·kPa/g to 6.67 m2·h·kPa/g. 14: A fiber reinforced cement siding according to claim 4, wherein the value of resistance to moisture permeation of the first painted portion is 2.67 m2·h·kPa/g to 6.67 m2·h·kPa/g, and the value of resistance to moisture permeation of the second painted portion is lower than that of the first painted portion. 15: A fiber reinforced cement siding according to claim 6, wherein the value of resistance to moisture permeation of the first painted portion is 2.67 m2·h·kPa/g to 6.67 m2·h·kPa/g, and the value of resistance to moisture permeation of the second painted portion is lower than that of the first painted portion. 16: A fiber reinforced cement siding according to claim 2, wherein the fiber reinforced cement siding has a longitudinal width of 2727 mm or more but 3030 mm or less, and a lateral width of 910 mm or more but 2000 mm or less. 17: An anti-seismic reinforced structure of a building wherein, in a structural frame comprising a pair of columns which are disposed to oppose each other to the right and left, an upper horizontal member and a lower horizontal member which are connected to each of the columns, a fiber reinforced cement siding according to claim 2 is in contact with the front surfaces of the upper horizontal member, the lower horizontal member and each of the columns, and is fixed to the contact portion on the front surfaces of the upper horizontal member, the lower horizontal member and each of the columns at predetermined intervals of 30 mm or more but 200 mm or less with a nail or a screw. 18: An anti-seismic reinforced structure of a building wherein, in a structural frame comprising a pair of columns which are disposed to oppose each other to the right and left, an upper horizontal member and a lower horizontal member which are connected to each of the columns, a fiber reinforced cement siding according to claim 2 being in contact with the structural frame in which a joint between the upper horizontal member or lower horizontal member and each of the columns or between these components are coupled with a metal fitting or a reinforcing metal, and the metal fitting or reinforcing metal is coupled in a position not interfering with the fiber reinforced cement siding with which it is in contact, or, counter bores are formed on the upper horizontal member or lower horizontal member and each column in the portions corresponding to the shape and thickness of the metal fitting or reinforcing metal so that the metal fitting or reinforcing metal does not interfere with the fiber reinforced cement siding, and the metal fitting or reinforcing metal is embedded and coupled in the counter bores, and is fixed to the contact portion on the front surfaces of the upper horizontal member, the lower horizontal member and each of the columns at predetermined intervals of 30 mm or more but 200 mm or less with a nail or a screw. 